The present invention relates to an eartip that conforms to the various shapes of human ear canals and provides an acoustic and pressure seal to the ear canal. More specifically, the present invention provides an eartip that seals to ear canals quicker, easier, and more comfortably than existing eartips. The conformable eartip provides a low coefficient of friction so that the eartip inserts into the ear canal without discomfort and allows for direct insertion into the ear canal without requiring preparatory compression of the foam. The conformable eartip creates a minimal amount of pressure against the ear canal when inserted, has the ability to significantly distort its shape to easily conform to non-circular ear canal shapes, conforms to bends in an ear canal, and provides a seal at varying depths within an ear canal.
There are three common categories of commercially available eartips, compressible foam, elastomeric, and custom earmolds. Compressible foam tips are nominally round foam cylinders that seal to the ear canal through compressibility of the foam. Compressible foam eartips are generally pre-formed by compressing the foam to reduce the outer diameter, allowing the tip to enter the ear canal before recovery of the foam to its relaxed diameter. As the foam expands in the ear canal it seals against the surface of the ear canal walls. Compressible foam eartips are often made of slow-recovery foam allowing for time between manually pre-compressing the foam and inserting it into the ear canal. A disadvantage of compressible foam eartips is that the eartips typically require the user to compress the foam prior to insertion into the ear canal.
Another common problem with compressible foam eartips is that the expansion of the foam in the ear canal can cause significant pressure against the ear canal wall. The excessive pressure against the ear canal wall may cause discomfort for a user of the eartip. Additionally, many existing compressible foam eartips do not conform to bends in an ear canal when attached to a sound tube of a hearing device. The inability of compressible foam eartips to conform to bends in an ear canal may prevent the eartips from providing a seal, particularly at deeper insertion depths. At shorter insertion depths, compressible foam eartips can be ineffective for excluding noise and can increase the amount of occlusion effect a user experiences when talking. A further disadvantage of existing compressible foam eartips is that a greater diameter of foam is typically needed to completely seal non-circular ear canals because the foam does not appreciably expand outward during recovery to its relaxed diameter.
Elastomer eartips are nominally round forms that are generally directly inserted into the ear canal without pre-compression. A common problem with elastomer eartips is that friction between the eartip and the ear canal wall can make the insertion of the eartip more difficult and less comfortable. A lubricant applied to the eartip can provide a reduction of friction but is seldom used because it can be messy and/or inconvenient. Additionally, existing elastomer eartips do not easily conform to the ear canal, which may cause significant pressure against the ear canal wall. The excessive pressure against the ear canal wall can cause discomfort for the user of the eartip.
Another disadvantage of existing elastomer eartips is that the eartips have difficulty sealing to the varying shapes of human ear canals. For example, many elastomer eartips may crease inward when inserted in non-circular ear canals thereby preventing a seal from forming between the eartip and the ear canal. Many existing elastomer eartips include thick and/or otherwise large core sections that inhibit the eartips ability to conform to bends in an ear canal. The inability of existing elastomer eartips to conform to bends in an ear canal may prevent a seal from forming between the eartips and the ear canal and/or can cause discomfort to a wearer because the ear canals may be forced to conform to the eartips. Also, elastomer eartips typically require deep insertion due to the nominal size of the eartips relative to the ear canal and the lack of conformability of the eartips. The ability to achieve a seal without deep insertion to the ear canal is particularly beneficial when the user is uncomfortable with inserting eartips into their ear canal, or for those where a deeper insertion is in itself uncomfortable.
Some elastomer eartips provide multiple sealing surfaces in incrementally increasing diameters, intended to allow the eartip to seal to a larger range of eartip diameters. Although multi-flange elastomer eartips may seal to a large variety of ear canal sizes, a significantly deeper insertion is typically needed for larger size ear canals and the insertion depth with smaller size ear canals may be limited. Another disadvantage of the multi-flange elastomer eartip style is a longer minimum length to accommodate the multiple sealing surfaces.
Custom earmolds are derived from a measurement or mold of the individual ear canal and are typically produced using silicone materials. Custom earmolds properly fit only the ear canal for which it was made, sealing to the ear canal by mating exactly with the ear canal shape. A common problem with custom earmolds is that friction between the material and the ear canal wall can make the insertion of the eartip more difficult and less comfortable. A lubricant applied to the eartip can provide a reduction of friction but is seldom used because it can be messy and/or inconvenient. Other problems with existing custom earmolds include the high cost of custom earmolds, the additional time needed for fitting and manufacturing the custom earmolds, and the inability to vary the insertion depth of the custom earmolds.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application.